Foldable electronic devices such as mobile phones, notebook computers, and PDAs comprise two device parts linked by a hinge. The hinge can be a single-axis construction wherein two hinge plates with coupling channels are separately connected to the device parts and a pin is inserted through the coupling channels as a pivot axis to join the two hinge plates. A single-axis hinge can also be constructed with a coil spring wrapped around a pivot pin wherein each end of the coil spring is secured to one device part. The hinge can also be a double-axis construction wherein two shafts are separately attached to the device parts and a coupling is engaged with the two shafts to allow the shafts to be used as two pivot axes. A foldable electronic device with a double-axis hinge is disclosed in Kurokawa (U.S. Patent Publication No. 2004/0266239 A1), for example. In Kurokawa, the double-axis hinge comprises two pivot shafts separately secured to two casings and a wire having a plurality of wound portions is used to connect the pivot shafts. This wire with wound portions acts like a winding spring having two spring ends, each secured to a casing.